Carbon dioxide corn germ oil extraction system

ABSTRACT

Supercritical carbon dioxide extraction of corn germ oil from corn germ utilizing extraction conditions adapted to a dry corn fractionation ethanol production process.

This United States patent application is a division of U.S. patentapplication Ser. No. 11/716,838, filed Mar. 12, 2007, now U.S. Pat. No.7,612,220, issued Nov. 3, 2009, which claims the benefit of U.S.Provisional Patent Application No. 60/858,107, filed Nov. 10, 2006 andU.S. Provisional Patent Application No. 60/838,642, filed Aug. 18, 2006,each hereby incorporated by reference herein.

BACKGROUND

Specifically, supercritical carbon dioxide extraction of corn germ oilfrom corn germ utilizing extraction conditions adapted to a dry cornfractionation ethanol production process. Generally, inventivesupercritical carbon dioxide extraction conditions which can be appliedto corn germ.

As shown in FIG. 1, conventional ethanol production systems (1) may millwhole corn (2) into a mixture of corn particles (3)(referred tohereinafter as “milled corn”) the mixture of particles including cornbran, corn endosperm and corn germ. The milled corn (3) can betransferred to the ethanol production process (4) which includes theconventional steps of fermentation, distillation, and dehydration togenerate an amount of ethanol (5). In the fermentation step, the milledcorn (3) may be combined with an amount of water and an amount ofalpha-amylase (or other enzyme capable of liquefying corn starch) togenerate a mash in which the starch of the corn endosperm is liquefied.The mash may be held for a period of time at a temperature of betweenabout 120 degrees Celsius (° C.) and about 150° C. to kill bacteria inthe mash. The mash may then be held at a temperature of between about90° C. and about 100° C. for a duration of time sufficient to achieve adesired level of liquefication of the starch. An amount of gluco-amylase(or other enzyme capable of generating fermentable sugars from theliquefied starch) added to the mash converts the liquefied starch tofermentable sugars, such as dextrose, in a process referred to assaccharification. Yeast can then be added to the mash to convert thesugars to an amount of ethanol (5) and an amount of carbon dioxide (6)(also referred to as “CO2”) along with other volatile organics. Theamount of carbon dioxide (6) can be placed in a storage unit (18) orsold in the marketplace. For sale into certain markets or for certainapplications, the amount of carbon dioxide (6) can be stripped of theother volatile organics and captured as an amount of purified carbondioxide (9). The fermented mash often referred to as “beer” comprises anamount of ethanol (5) in a concentration of about eight percent to abouteighteen percent by weight, other liquids, and non-fermentable solids.The amount of ethanol (5) in the beer can be separated and concentratedto about 190 proof by conventional distillation techniques anddehydrated by application to molecular sieve to produce a dehydratedethanol of about 200 proof. The about 200 proof ethanol may be combinedwith up to about five percent denaturant to generate an amount of fuelgrade ethanol (10) which can be placed in the storage unit (18) andsubsequently sold.

The stillage which remains after distillation of the beer can comprisean amount of liquid typically referred to as “thin stillage” and anamount of remaining solids typically referred to as the “distillersgrains”. The thin stillage can be separated from the distillers grains(for example by centrifugation). The distillers grains can be dried byevaporation of the remaining thin stillage. The thin stillage can beconcentrated by evaporation of water to generate a syrup containingabout twenty percent solids to about sixty percent solids (also referredto as “condensed distiller soluble”). The syrup can be recombined withthe dried distillers grains to generate an amount of distillers driedgrain with solubles (7)(“DDGS”). The DDGS can be sold as animal feed(8).

Even though there is an increasing demand for fuel ethanol (10)worldwide and an increasing amount of research in ethanol production,there remain substantial unresolved problems with respect toconventional ethanol production.

A first substantial problem with the conventional ethanol productionprocess above-described and referring again to FIG. 1 can be that theamount of thermal energy (11)(or energy Btus or Btus) utilized by theconventional ethanol production process (4), including the steps offermentation, distillation and dehydration, and by-product handling,which results in about a gallon of fuel ethanol (5), and a correspondingamount of DDGS (7) and carbon dioxide (6) may utilize an amount ofthermal energy (11) of between about 30,000 and 40,000 British thermalunits (hereinafter “Btu”). This amount of thermal energy (11) istypically generated by burning a corresponding amount of fossil fuel(12) such as oil, coal oil, coal or natural gas.

To reduce the amount of fossil fuels (12) utilized to provide the amountof thermal energy (11) required for the ethanol production process (4),an amount of the DDGS (7) may be burned to produce a part of the amountof thermal energy (11) required as described by United States PatentApplication No. 2003/0019736A1.

Alternately, referring to FIG. 2, U.S. Patent Application No.60/838,642, hereby incorporated by reference, inventive dry mill kernelfractionation processes (17) which fracture kernels of grain (13), suchas cleaned conditioned corn, and isolate process fractions which includethe pericarp (also referred to as “bran”), the germ, and the endospermcan be utilized to reduce the amount of thermal energy (11) required bythe ethanol production system (4) or to generate an amount of thermalenergy (11) without the use of fossil fuels (12). As shown in FIG. 2,the isolated endosperm fraction (14) can be introduced into the ethanolproduction process (4) without substantial amounts of the germ fraction(16) or the bran fraction (15). By introducing only the endospermfraction (14) into the ethanol production process (4) an increasedamount of ethanol (5) and fuel ethanol (10) can be generated per unit offermented material. As the amount of ethanol (5) per unit of fermentedmaterial increases, the amount of thermal energy (11) required toproduce an amount of ethanol (5) decreases. However, use of theinventive dry mill kernel fractionation processes (17) described alsogenerates an isolated germ fraction (16) and the isolated bran fraction(15) which must be further processed, placed in the storage unit (18),sold, or disposed.

Referring now to FIGS. 3 and 4, various embodiments of the inventive drymill corn fractionation process (17) as described by U.S. PatentApplication No. 60/858,107 and International Patent Cooperation TreatyPatent Application No. PCT/US06/45193, each hereby incorporated byreference, can utilize the isolated germ fraction (16) and the isolatedbran fraction (15)(or isolated components thereof whether in whole or inpart or separately or in various combinations) to generate an amount ofthermal energy (11) to replace in whole or in part the amount of thermalenergy (11) conventionally produced by burning fossil fuels (12). Withrespect to the corn germ fraction (16), extraction of the corn germfraction (16) with an amount of supercritical carbon dioxide (28) cangenerate an amount of corn oil (23) which can be placed in the storageunit (18), sold, burned to produce thermal energy (11) or can beconverted to biodiesel (27) which can placed in the storage unit (18),sold or burned as a fuel (33) to produce an amount of thermal energy(11) separately or in combination with an amount of any one or more ofcondensed distiller soluble (30), fusel oil (29), ethanol (5), orfractionated corn gluten meal (31). As to certain embodiments of theinvention, the amount of thermal energy (11) can be transferred to aboiler (34) which can produce steam which coupled to a turbine (36) cangenerate an amount of electricity (37).

A substantial problem with respect to corn germ oil extraction (21) ofthe corn germ fraction (16) to produce an amount of corn germ oil (23)can be that conventional carbon dioxide extraction methods whetherperformed with carbon dioxide or with supercritical carbon dioxideutilize extraction conditions which: may not extract (21) a substantialportion of the amount of the corn oil (23) contained in the corn germfraction (16), or may extract the amount of corn oil (23) contained inthe corn germ fraction (15) at a rate which requires greater than aboutthirty minutes (the term “about” means greater or lesser than the valueor range of values stated by 10 percent, but not does not limit anyvalue or range of values to this broader definition and each value orrange of values preceded by the term “about” also includes in thealternative the absolute value or range of values stated), or may notextract an amount of corn oil (23) from the corn germ fraction (16) ofbetween about 18 weight percent to about 30 weight percent (such weightpercent including any processing of the corn germ to remove a part ofthe oil prior to extraction with carbon dioxide or supercritical carbondioxide), or may not extract 90 percent or more of the extractableamount of corn oil (23) in the amount of corn germ fraction (16)), orrequires utilization of an amount of supercritical carbon dioxide (28)to the amount of corn germ fraction (16) extracted of greater than about5 to 1 (wt./wt.) (as a non-limiting example, ratios of 5 to 1 or lessmay be preferred in certain embodiments of a dry mill corn fractionationprocess (17) in the context of ethanol production), or of greater thanabout 7 to 1 (as a non-limiting example, ratios of 7 to 1 or less may bepreferred in other embodiments of the dry mill corn fractionationprocess (17) in the context of ethanol production), or may greater thanabout than 12 to 1 (as a non-limiting example, 12 to 1 or less may bepreferred in yet other embodiments of the dry mill corn fractionationprocess (17) in the context of ethanol production).

As such, conventional carbon dioxide extraction methods may be in wholeor in part impracticable or incompatible with the process rates orefficiency rates required in the context of a dry mill kernelfractionation ethanol production process (17), or may not be competitiveor commercially feasible relative to other conventional methods, or aresimply less desirable to extraction conditions which allow between about18 weight percent to about 30 weight percent of the corn germ fraction(16)(or greater weight percents for corn germ having greater weightpercentage extractable corn oil such as about 45 weight percent corngerm oil) to be extracted as corn oil (23) utilizing a ratio ofsupercritical carbon dioxide (28) to corn germ fraction (16) of notgreater than about 12.0 to 1 (wt./wt.), or not greater than 7 to 1, ornot greater than 5 to 1, or of greater than 2 to 1 depending on theapplication. Understandably, the inventive corn germ fraction (16)extraction conditions described herein may confer an advantage in otherapplications outside of ethanol production systems (17) described hereinor incorporated by reference and the invention is not so limited.

Now referring primarily to FIG. 4, another substantial problem withconventional methods of corn germ oil extraction (21) may be that theextracted corn germ fraction (22) (also referred to as “germ cake”) maycontain an amount of water (25) subsequent to corn oil extraction (21),a portion of which may require evaporation or otherwise removed beforethe germ cake (22) prior to placement in the storage unit (18) or sold,or which increases the number steps to process the germ cake (22) into aparticular germ cake byproduct (27) (such as a germ cake animal feed) ormakes the steps to produce a particular germ cake byproduct (27) morecostly. As an example, further described below, the condensed distillersoluble (24) above-described can be mixed with the germ cake (22) butthe amount of water (25) contained by the germ cake (22) subsequent tomixing which is in excess of about fourteen percent by weight (or inexcess of a pre-selected or desired amount of water) must be removed. Assuch, any reduction in the amount of water (25) contained by the germcake (22) subsequent to corn oil extraction (21) can reduce the amountof water (25) that must be removed from the germ cake (22) or removedfrom a mixture of germ cake (22) and condensed distiller soluble (24) toachieve an amount of water in a germ cake animal feed (27) of less thanfourteen percent by weight or other water content desirable based uponthe application.

The present inventive supercritical carbon dioxide extraction conditionsof the corn germ fraction (16) described herein address each of theabove-mentioned problems related to conventional corn germ oilextraction from corn germ (16).

SUMMARY OF THE INVENTION

Accordingly, a broad object of the invention can be to providesupercritical carbon dioxide extraction of corn germ oil from corn germutilizing extraction conditions adapted to a dry corn fractionationethanol production process.

A second broad object of the invention can be to provide inventivesupercritical carbon dioxide extraction of corn germ oil from corn germ.The inventive supercritical carbon dioxide extraction conditions as tocertain embodiments of the invention can extract greater amounts of cornoil from the same amount of corn germ fraction compared withconventional corn germ extraction conditions. Additionally, theinventive supercritical carbon dioxide extraction conditions can extractthe same or greater amounts of corn oil from the corn germ fraction in alesser duration of time, or can extract an amount of corn oil from anamount of corn germ fraction of between about 18 percent by weight toabout 30 percent by weight (or greater weight percentage for corn germcontaining for example 45 percent corn oil by weight) which as tocertain embodiments of the invention can be in a lesser duration oftime. An additional advantage of utilizing the inventive supercriticalcarbon dioxide extraction conditions can be a reduction in the amount ofsupercritical carbon dioxide utilized to extract the same or greateramount of corn oil from the corn germ fraction which as to certainembodiments of the invention can provide a ratio of supercritical carbondioxide to corn germ fraction extracted of not greater than about 12 to1 (wt./wt.), or as to certain embodiments of the invention not greaterthan about 7.0 to 1, or as to certain embodiments of the invention notgreater than about 5.0 to 1.0, or as to certain embodiments of theinvention between about 2.0-5.0 to 1.0.

A third broad object of the invention can be to provide an extractedcorn germ fraction containing an amount of water which can be less thanthe amount of water contained by conventional corn germ oil extractionprocesses.

A fourth broad object of the invention can be to provide a corn germanimal feed which includes the germ cake extracted with supercriticalcarbon dioxide (whether by conventional conditions or the inventiveconditions described herein) mixed with an amount of condensed distillersoluble and a method of manufacturing such animal feed which can utilizeless thermal energy to bring the mixture to a desired amount of water.

Naturally, further objects of the invention are disclosed throughoutother areas of the specification, drawings, and claims.

A BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides a flow diagram of the conventional fuel ethanolproduction technology.

FIG. 2 provides a flow diagram of a particular embodiment of aninventive fuel ethanol production technology utilizing grainfractionation products.

FIG. 3 provides a flow diagram of a particular embodiment of theinventive fuel ethanol production technology utilizing grainfractionation products.

FIG. 4 provides a flow diagram of a particular embodiment of theinventive fuel ethanol production technology utilizing grainfractionation products.

FIG. 5 provides a flow diagram of a particular embodiment of a corn germextraction system.

FIG. 6 provides an enlarged portion of the flow diagram shown in FIG. 5further providing a cut away of a part of an extraction vessel showingthe corn germ extraction zone containing an amount of corn germ.

FIG. 6A provides an enlargement of one of the plurality of particlesincluded in the amount of corn germ contained in the corn germextraction zone further illustrating the corn germ matrix.

FIG. 7 provides a graph which plots solvent to feed ratio againstpercent weight of feedstock (weight of corn germ) extracted for certainembodiments of the inventive corn germ extraction conditions.

FIG. 8 provides a graph which plots solvent to feed ratio againstpercent weight of feedstock (weight of corn germ) extracted for certainembodiments of the inventive corn germ extraction conditions.

FIG. 9 provides a graph which plots solvent to feed ratio againstpercent weight of feedstock (weight of corn germ) extracted for certainembodiments of the inventive corn germ extraction conditions.

FIG. 10 provides a graph which plots solvent to feed ratio againstpercent weight of feedstock (weight of corn germ) extracted for certainembodiments of the inventive corn germ extraction conditions.

FIG. 11 provides a graph which plots solvent to feed ratio againstpercent weight of feedstock (weight of corn germ) extracted for certainembodiments of the inventive corn germ extraction conditions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Specifically, supercritical carbon dioxide extraction of corn germ oilfrom corn germ utilizing extraction conditions adapted to a dry millcorn fractionation ethanol production process. Generally, inventivesupercritical carbon dioxide extraction conditions which can be appliedto corn germ to achieve at least one of: greater amounts of corn oilfrom the same amount of corn germ, generate the same amount of corn oilor greater amounts of corn oil from an amount of corn germ in a lesserduration of time, utilize lesser amounts of supercritical carbon dioxideto generate the same or greater amounts of corn oil from an amount ofcorn germ.

Now referring primarily to FIGS. 2-4, a corn germ fraction (16)(alsoreferred to in part as “an amount of corn germ”) can be generated asabove-described or can be generated by any conventional milling processor other corn germ production means. While certain aspects of theinventive supercritical carbon dioxide extraction conditions describedherein were adapted for use with the corn fractionation ethanolproduction systems (17) shown by FIGS. 2-4, the invention is not solimited and the inventive supercritical carbon dioxide extractionconditions can be adapted for use in a wide variety applications whichextract an amount of corn germ oil (23) from an amount of corn germ(16).

Now referring primarily to FIGS. 3 and 4, the amount of corn germ (16)can pass through a comminutor (38) to be reduced to a plurality of corngerm particles (39) having a particle configuration (whether by size,range of size, or shape or in various permutations and combinationsthereof) suitable for use with the inventive extraction conditionsdescribed herein. The particle configuration of the plurality of corngerm particles (39) obtained (whether by sieving, sifting, independentof or in combination with use of a comminutor (38)) allows the amount ofsupercritical carbon dioxide (9) to fluidically engage the amount ofcorn germ (16) in a manner which allows the amount of corn oil (23)(orthe extractable portion of corn oil (23)) contained in the amount corngerm (16) to be solubilized and removed from the amount of corn germ(16) at a particular combination of: a temperature, a pressure, a ratioof supercritical carbon dioxide (9) to the amount of corn germ(16)(wt./wt.), and pre-selected duration of time (the “extractionevent”). The inventive extraction conditions can be utilized to overcomethe un predictability of a number of factors which affect the extractionevent including without limitation differences in the corn germ matrix(40)(see FIG. 6) presented by the amount corn germ (16) which can varyin terms of the porosity, the void volume, the pore configuration orrange of pore configurations, resistance to alteration of the corn germmatrix (40) to pressure, resistance to alteration of the corn germmatrix (40) to temperature, the amount of corn germ oil (23) containedby the amount of corn germ (16), the solubility of the corn germ oil(23) or components of the amount of corn germ oil (23) in the amountsupercritical carbon dioxide (9), or the like.

Now referring primarily to FIGS. 5 and 6, the plurality of corn germparticles (40) generated from the amount of corn germ (16) must becompatible with a given corn germ oil extraction system (41). A firstconfiguration of the plurality of particles (40) which comprise theamount of corn germ (16) may be compatible with a particularconfiguration of a corn germ oil extraction system (41) under a firstset of extraction conditions and incompatible with the same corn germoil extraction system (41) under a second set of extraction conditions.For example, under a first set of extraction conditions, the pluralityof particles (39) may allow sufficient flow of the amount ofsupercritical carbon dioxide (9) through one or a plurality of extractorvessels (42)(further described below) while under a second set ofextraction conditions, the plurality of particles may restrict flowthrough one or more of the plurality of extractor vessels (42) such asby reduction of flow of the amount of supercritical carbon dioxidethrough frits which may be used to retain the plurality of particles(39) in the plurality of extractor vessels (42).

With respect to certain embodiments of the invention utilized with theabove-described corn fractionation ethanol production systems (17)(orother corn germ production means), the comminutor (38) can be utilizedto reduce the amount of corn germ (16) to the plurality of corn germparticles (39) having a configuration suitable for use with theinventive corn germ oil extraction conditions described herein. Thecomminutor (38) can operate to reduce the amount of corn germ (16) tothe plurality of particles (39) suitable for use with the invention. Asto certain non-limiting embodiments of the invention the comminutor (38)can provide a particle configuration which can pass through a 20 meshscreen each opening having a width of opening of about 0.33 inches orabout 850 μM but not through a 100 mesh screen each opening having awidth of opening of about 0.0060 inches or about 150 μM, or can operateto reduce the amount of corn germ (16) to a plurality of particles (39)which pass through about a 30 mesh sieve each opening having a width ofopening of about 0.21 inches or about 540 μM but not through a 100 meshscreen. As too certain embodiments of the invention the comminutor (38)can operate to reduce the amount of corn germ (16) to a plurality ofparticles (39) which pass through a 20 mesh sieve or a 30 mesh sievewithout any limitation as to a lower limit on particle size. Anon-limiting example of a comminutor (38) suitable for use with theinvention can be a hammermill adjusted to generate the plurality ofparticles (39) of one or more of the above-described configurations. Asbut one example, a hammermill available from Bliss Industries, Inc.,Ponca City, Okla. can be utilized. With respect to certain embodimentsof the invention, one or more sifters, or separators, or air lifts canbe utilized separately or in combination with the comminutor (38) togenerate the plurality of particles (39) which are not within thedefined particle configuration. Each of the trials set out by Example 1included that portion of an amount corn germ which was ground and passedthrough a 30 mesh sieve. It is not intended that the above describedparticle configurations be limiting with respect to the broader range ofparticle configurations which can be utilized with the inventiveextraction conditions further described below.

Now referring primarily to FIGS. 5 and 6, the corn germ oil extractionsystem (41) can include an extractor assembly (43) such as the cascadeextractor shown in the Figure which provides one or a plurality ofextractor vessels (42) each of which define a corn germ extraction zone(43) inside of which the amount of corn germ (16) which can becomminuted to provide a plurality of particles (39) as above-describedcan be located for fluidic engagement with an amount of supercriticalcarbon dioxide (9) to perform the extraction event. Each of theextraction vessels (42) can independently perform an extraction event onthe amount of corn germ (16) in manner which allows at least oneextractor vessel (42A)(shown in broken lines) to come off line for aduration of time after the extraction event sufficient to remove theamount of extracted corn germ (22) and introduce an amount of corn germ(16) for a subsequent extraction event. Each of the plurality ofextractor vessels (42) can be coupled to a heat source (45) whichgenerates an amount of heat sufficient to maintain the amount ofsupercritical carbon dioxide (9) at a temperature of between about 70°C. and about 120° C. during fluidic engagement with the amount of corngerm (16) located inside said corn germ extraction zone. The heat source(45) can be coupled to a temperature adjustment element (46) which canmonitor temperature of the amount of supercritical carbon dioxide (9) inthe corn germ extraction zone (43) or can monitor other conditionsoutside of the corn germ extraction zone such as the amount of corn oil(23) solubilized in the amount of supercritical carbon dioxide (9) (the“effluent” (46)) flowing from the corn germ extraction zone (43), orother measure of the efficiency of the extraction event to allowcontinuous adjustment of the temperature of the amount of supercriticalcarbon dioxide (9) in the corn germ extraction zone (43) to maintain apreselected temperature, a preselected temperature profile, or apreselected corn germ extraction efficiency profile based on monitoringthe effluent (46) from the corn germ extraction zone. The extractorassembly further includes a plurality of conduits and valves (47)configured to allow transfer of the amount of supercritical carbondioxide (9) into and away from the corn germ extraction zone (43). Whilea particular example of a cascade extractor is shown in FIG. 5, it isnot intended that this configuration of cascade extractor be limitingwith respect to the numerous and varied configurations of cascadeextractors which could be utilized or made compatible with the inventivesupercritical carbon dioxide extraction conditions herein described orutilized with or made compatible with other configurations of extractorassemblies such as a continuous feed extractor which continuouslyintroduces an amount of corn germ (16) into at least one extractionvessel (42) counter current to the continuous introduction of an amountof supercritical carbon dioxide (9).

The corn oil extraction system (41) can further include a carbon dioxiderecycle assembly (48) which can include at least one separator (49)having at least one separator vessel (50) which defines at least onecorn oil separation zone (51) in which the amount of corn oil (23)extracted from the amount of corn germ (16) can be separated from theamount of supercritical carbon dioxide (9) by establishing one or aplurality of corn oil separation conditions in the at least one corn oilseparation zone (51). The at least one separator (49) further includes aplurality of separator conduits and valves (52) configured to allowtransfer of the amount of supercritical carbon dioxide (9) into and awayfrom the at least one corn oil separation zone (50 and transfer of theseparated amount of corn oil (23) away from the at least one corn oilseparation zone (51).

The carbon dioxide recycle assembly (48) can further include a condenser(52) which provides condensing conditions to establish the separatedamount of carbon dioxide (9) in a phase compatible with a pressuregenerator (53) which establishes and maintains the amount ofsupercritical carbon dioxide at pressure between about 7,000 psi andabout 12,000 psi in the corn germ extraction zone (43). The pressuregenerator (53) can be coupled to a pressure adjustment element (54)which can monitor the pressure of the amount supercritical carbondioxide (9) in the corn germ extraction zone (43) or can monitor otherconditions outside of the corn germ extraction zone (43) such as theamount of corn oil solubilized in the effluent (46), or other measure ofthe efficiency of the extraction event to allow continuous adjustment ofthe pressure of the amount of supercritical carbon dioxide (9) in thecorn germ extraction zone (43) to establish or maintain a preselectedpressure, a preselected pressure profile, or a preselected corn germextraction efficiency profile based on monitoring the effluent (46) fromthe corn germ extraction zone (43).

Now referring primarily to FIG. 5 and Table 1 set out below, it can beunderstood that if the flow rate of the supercritical carbon dioxide (9)in the corn germ extraction zone (43) has a constant velocity (althoughin practice the velocity can also be varied) then the effects of thealteration of the supercritical carbon dioxide extraction conditions asto a temperature and a pressure can be evaluated as to effect on a ratioof the amount of supercritical carbon dioxide (9) at a given temperatureand pressure to the amount of corn germ (16)(wt./wt.) (also referred toas the “solvent to feed ratio”) to reach a particular extraction eventend point such as an amount of corn oil (23) of about twenty percent ofthe amount of the corn germ (16) (wt./wt.). For example, if the solventto feed ratio is about 20 to 1 to obtain extraction of an amount of corngerm oil (23) of twenty percent of the weight of the amount of the corngerm (16) extracted, then for each ton of corn germ oil (23) extractedabout twenty tons of supercritical carbon dioxide (9) would be utilized.If the solvent to feed ration is about 2 to 1, then for each ton of corngerm oil (23) extracted two tons of supercritical carbon dioxide (9)would be utilized and so forth. The inventive dry corn fractionationplants above-described as a non-limiting example can process betweenabout 3,000 tons and 5,000 tons of whole corn (2) per day to generateabout 250 tons to about 400 tons of corn germ fraction (16). If the cornoil extraction system (41) processes 300 tons of corn germ fraction (16)per day at a solvent to feed ratio of about 20 to 1 then about 6,000tons of supercritical carbon dioxide (9) would pass through the corngerm extraction zone (43) of the extractor assembly and be recovered bythe carbon dioxide recycle assembly (48) per day. However, if the cornoil extraction system (41) processes the same 300 tons of corn germfraction (16) per day at a solvent to feed ratio of about 2 to 1 thenonly 600 tons of supercritical carbon dioxide (9) would pass through thecorn germ extraction zone (43) of the extractor assembly (43) and berecovered by the carbon dioxide recycle assembly (48) per day.

Even if the configuration of the extractor assembly (43) remainssubstantially the same regardless of the solvent to feed ratio becausethe mass of the amount of corn germ (16) extracted remains constant, itcan be understood that at least the components of the carbon dioxiderecycle assembly (48) would be necessarily scaled upward as solvent tofeed ratio increases over the 10 fold range shown in Table 1. As thesolvent to feed ratio increases both the capital costs and the cost tooperate the corn germ oil extraction system (41) also increase. Corngerm oil extraction systems (41) which adapted to or built to utilizethe inventive solvent to feed ratios in the range of about 2 to 1 toabout 6.5 to 1 can be extremely economically operate with respect toboth capital cost and operating costs while corn oil extraction systems(41) which are adapted to or utilize the inventive solvent to feedratios in the range of about 7.0 to 1 to about 18.5 to 1 are likely beonly marginally economical to operate, and corn oil extraction systems(41) which utilize solvent to feed ratios of greater than 20 to 1 arelikely to be impractical to build or uneconomical to operate.

TABLE 1 Effect of Pressure and Temperature on Extraction Efficiency asRepresented by Solvent/Feed Ration to Reach 20% of Feedstock wt/wtExtraction. Solvent/Feed Ration Temperature to Reach 20% of Pressure (°C.) Feedstock wt/wt Extraction 9300 110 ~2.0 9000 100 ~2.5 9000 80 ~3.59300 80 ~4.5 9580 87.3 ~5.0 8000 95 ~5.5 7500 100 ~5.5 8000 85 ~6.0 850090 ~6.5 7500 90 ~7.0 7000 80 ~8.0 6000 85 ~10 5800 57 ~13.5 5000 80 >206000 70 ~23 5000 100 >25 1600 20 >30

Now referring primarily to FIG. 7 and Table 1, certain extraction eventsare plotted to show the solvent to feed ratio as a function of thepercent of the weight of the amount of the corn germ (16) extracted forcorn germ extraction conditions which result in solvent to feed ratiosof less than about 5 to 1 to achieve extraction of an amount of corn oil(23) of about twenty percent of the weight of the amount of corn germ(16) extracted. It is not intended that the examples shown in Table 1 belimiting with respect to the weight percent of the amount of corn oilwhich can be achieved utilizing the stated solvent to feed ratios, andsignificantly greater weight percent corn germ oil may be extracted froman amount of corn germ having significantly greater amounts ofextractable corn germ oil (23), as a non-limiting example forty fivepercent extractable corn oil by weight. Similarly, these examples arenot intended to preclude applications to an amount of corn germ oil (23)having a part of the extractable corn germ oil (23) removed prior toextraction with an amount of supercritical carbon dioxide in which casethe remaining extractable amount of corn germ oil may be less thantwenty percent by weight. As such the term “an amount of corn germ” isintended to include any source of corn germ or pre-processed corn germwhether or not a part of the corn germ oil (23) has been prior removedby another process(es) prior to extraction with the invention extractionconditions described herein.

As can be understood from the plots shown, fluidically engaging anamount of supercritical carbon dioxide (9) with an amount of corn germ(16) at a pressure of between about 9,000 psi and about 10,000 psi andat temperatures of between about 80° C. and about 110° C. (even greaterpressures of up to 12,000 psi and even greater temperatures of up toabout 120° C. can be utilized) can achieve solvent to feed ratios ofless than about 5 to 1 and even about 2 to 1 or even less than about 2to 1 as shown by the examples performed at 9,300 psi and 110° C. (about1.75 to 1)(see also Examples below). Additionally, dramatic reduction ofsolvent to feed ratios can be achieved by increasing temperature whenthe pressure is established at between about 9,000 psi to about 10,000psi (or even greater pressure up to about 12,000). It is believed thatthese inventive solvent to feed ratios of less than about 5 to 1, orabout 2 to 1, or less that about 2 to 1 and the corn germ extractionconditions utilized to achieve these solvent to feed ratios of betweenabout 9,000 psi and about 10,000 psi and between about 85° C. and about110° C. (or up to about 12,000 psi and up to about 120° C.) have notbeen taught prior to the invention.

Now referring primarily to FIG. 8 and Table 1, certain extraction eventsare plotted to show solvent to feed ratio as a function of the percentof the weight of the amount of the corn germ (16) extracted for corngerm extraction conditions which result in solvent to feed ratios ofabout 5 to 1 to about 7.0 to 1 to achieve extraction of an amount ofcorn oil (23) of about twenty percent of the weight of the amount ofcorn germ (16) extracted. As can be understood from the plots shown,fluidically engaging supercritical carbon dioxide with an amount of corngerm at a pressure of between about 7,500 and about 8,500 psi attemperatures of between about 90° C. and about 100° C. can achievesolvent to feed ratios of between about 5 to 1 to about 7 to 1. It isbelieved that these advantageous solvent to feed ratios of between 5 to1 to about and 7 to 1 and the particular corn germ extraction conditionsutilized to achieve these solvent to feed ratios of between about 7,500psi and about 8,500 psi and between about 85° C. and about 100° C. havenot been taught prior to the invention.

Now referring primarily FIG. 9 and Table 1, certain extraction eventsare plotted to show the solvent to feed ratio as a function of thepercent of the weight of the amount of the corn germ extracted for corngerm extraction conditions which result in solvent to feed ratios ofbetween about 7.0 to 1 and about 10 to 1 to achieve extraction of anamount of corn oil of about twenty percent of the weight of the amountof corn germ extracted. As can be understood fluidically engagingsupercritical carbon dioxide with an amount of corn germ at a pressureof between about 6,000 psi and about 7,500 psi at temperatures ofbetween about 80° C. and about 90° C. can achieve solvent to feed ratiosof between about 7 to 1 to about 10 to 1. It is believed that theseadvantageous solvent to feed ratios of between 7 to 1 to about and 10 to1 and the particular corn germ extraction conditions utilized to achievethese solvent to feed ratios of between about 6,000 psi and about 7,500psi and between about 80° C. and about 90° C. have not been taught priorto the invention.

Now referring primarily to FIG. 10 and Table 1, certain extractionevents are plotted to show the solvent to feed ratio as a function ofthe percent of the weight of the amount of the corn germ extracted forcorn germ extraction conditions which show that pressure lower thanabout 6,000 psi and temperatures of about 60° C. result in solvent tofeed ratios of greater than about 10 to 1 to achieve extraction of anamount of corn oil of about twenty percent of the weight of the amountof corn germ extracted. Solvent to feed ratios greater than about 10:1are likely to be impractical or uneconomic in the context of cornfractionation production systems as above-described.

Now referring primarily to FIG. 11 and Table 1, certain extractionevents are plotted to show the solvent to feed ratio as a function ofthe percent of the weight of the amount of the corn germ (16) extractedfor corn germ extraction conditions which result in solvent to feedratios of greater than about 20 to 1 to achieve extraction of an amountof corn oil of about twenty percent of the weight of the amount of corngerm extracted. Solvent to feed ratios greater than about 10:1 arelikely to be impractical or uneconomic in the context of cornfractionation production systems as above-described.

Also, as can be seen by the trials run at 5,000 psi that a substantialincrease temperature from about 80° C. to 100° C. can actually operateto adversely increase the solvent to feed ratio. This teaches away fromthe inventive corn germ extraction conditions above described which showsubstantial reductions in solvent to feed ratio as temperature increasesand may account for higher temperatures and pressures not being priordiscovered.

Again referring primarily to FIG. 5, the corn oil extraction system (41)can further provide a water removal element (55) which operates toremove an amount of water from the amount of supercritical carbondioxide (9) prior to fluidic engagement with the amount of corn germ(16) in the corn germ extraction zone (43) to establish an amount ofwater (56) contained by the amount of supercritical carbon dioxide (9)of about one percent to about seven percent by weight or an amount ofwater (56) by weight which upon fluidic engagement with the amount ofcorn germ (16) in the corn germ extraction zone (43) reduces the amountof water (57) contained by the amount of extracted corn germ (22)(seeFIGS. 3 and 4) to between about one percent to about fourteen percent byweight.

Again referring primarily to FIG. 4, a corn germ animal feed (58) can beproduced by mixing (59) the amount of extracted corn germ (22) havingthe amount of water (57) reduced to between about one percent to aboutseven percent by weight with an amount of condensed distiller soluble(30) having a solids content of between about thirty percent to aboutsixty percent by weight. In one embodiment of the inventive method ofproducing the corn germ animal feed (58) above described, the amount ofcondensed distiller soluble (30) mixed (59) with the amount of extractedcorn germ (22) increases the amount of water (57) contained by theamount of extracted corn germ to an amount of water (57) by weight whichdoes not exceed about fourteen percent water or does not exceed anamount of water (57) by weight which requires the additional step ofdrying (60) the animal feed prior to placement in the storage unit (18)or sold. In an alternate embodiment of the inventive method of producingthe corn germ animal feed above described, the amount of condenseddistiller soluble (30) mixed with the amount of extracted corn germ (22)to introduce the desired amount of solids increases the amount of water(57) contained by the amount of extracted corn germ (22) above fourteenpercent by weight or above an amount of water by weight which requiresremoval of an amount of the water (57) then contained by the amount ofextracted corn germ (22). However, this process still confers anadvantage because less water needs to be removed (60) than wouldconventionally be required if the condensed distiller soluble (30) wasmixed (59) with an amount of corn germ (16) or with an amount ofextracted corn germ (22) which typically contains an amount of water(57) of between about seven percent to about fourteen percent by weightor containing a greater amount of water (57) than between about onepercent and about seven percent by weight. By avoiding any removal (60)of the amount of water (57), or by reducing the amount of water (57) tobe removed (60), contained by the amount of extracted corn germ (22)subsequent to mixing (59) with the amount of condensed distiller soluble(30), a lesser amount of fuel (33) or thermal energy (11) can beconsumed to produce the same amount of corn germ animal feed (58) asabove-described. As to those embodiments of the animal feed whichrequire removal of a part of the amount of water (27) contained by theextracted corn germ (22) after mixing (59) with the amount of condenseddistiller soluble (30), embodiments of the invention can further includea dryer (60) capable of reducing the amount of water (57) contained bythe amount of corn germ (22) mixed (59) with said amount of condenseddistillation soluble (30) having the amount of solids in the range ofabout 20 percent by weight to about 60 percent by weight to betweenabout eight percent by weight to about fourteen percent by weight.Because the amount of water to be removed can be less when the animalfeed is prepared by the above-described method, the dryer (60) can be aless expensive type of dryer (60) such as a rotary dryer. A rotary dryersuitable for use with the invention can be obtained for example from FMCCorporation or ICM, Inc.

EXAMPLE 1

A series of trials were conducted to assess the effect of temperatureand pressure on the carbon dioxide extraction (21) of corn oil (23) fromthe corn germ fraction (16) obtained from the corn fractionation process(13).

-   Trial 1: 100 ml extraction of corn germ: 9200 psi and 90° C. 35.55 g    of corn germ feedstock was ground and sieved, and placed in a 100 ml    extraction vessel and extracted with pure carbon dioxide at a    pressure of 9200 psi and a temperature of 90° C. The flow rate was 4    liters/minute. A total of 8.33 g of yellow corn oil was extracted    (23.43% by weight of feedstock). The solvent to feedstock ratio was    <8 (S/F<8).-   Trial 2: 100 ml extraction of corn germ: 7500 psi and 80° C. 35.55 g    of corn germ feedstock was ground and sieved, and placed in a 100 ml    extraction vessel and extracted with pure carbon dioxide at a    pressure of 7500 psi and a temperature of 80° C. The flow rate was 4    liters/minute. A total of 6.26 g of yellow corn oil was extracted    (17.60% by weight of feedstock).-   Trial 3: 100 ml extraction of corn germ: 6000 psi and 70° C. 35.55 g    of corn germ feedstock was ground and sieved, and placed in a 100 ml    extraction vessel and extracted with pure carbon dioxide at a    pressure of 6000 psi and a temperature of 70° C. The flow rate was 4    liters/minute. A total of 7.33 g of yellow corn oil was extracted    (20.61% by weight of feedstock). Solvent/feed ratio of about 15/1.-   Trial 4: 100 ml extraction of corn germ: 5000 psi and 60° C. 35.55 g    of corn germ feedstock was ground and sieved, and placed in a 100 ml    extraction vessel and extracted with pure carbon dioxide at a    pressure of 5000 psi and a temperature of 60° C. The flow rate was 4    liters/minute. A total of 7.38 g of yellow corn oil was extracted    (20.75% by weight of feedstock). Solvent/feed ratio of about 25/1.-   Trial 5: 100 ml extraction of corn germ: 8000 psi and 85° C. 35.55 g    of corn germ feedstock was ground and sieved, and placed in a 100 ml    extraction vessel and extracted with pure carbon dioxide at a    pressure of 8000 psi and a temperature of 85° C. The flow rate was 4    liters/minute. A total of 7.57 g of yellow corn oil was extracted    (21.29% by weight of feedstock). Solvent/feed ratio of about 10/1.-   Trial 6: 100 ml extraction of corn germ: 8500 psi and 90° C. 35.55 g    of corn germ feedstock was ground and sieved, and placed in a 100 ml    extraction vessel and extracted with pure carbon dioxide at a    pressure of 8500 psi and a temperature of 90° C. The flow rate was 4    liters/minute. A total of 7.62 g of yellow corn oil was extracted    (21.43% by weight of feedstock). Solvent/feed ratio of about 12/1.-   Trial 7: 100 ml extraction of corn germ/7500 psi and 90° C. 35.55 g    of corn germ feedstock was ground and sieved, and placed in a 100 ml    extraction vessel and extracted with pure carbon dioxide at a    pressure of 7500 psi and a temperature of 90° C. The flow rate was 4    liters/minute. A total of 7.50 g of yellow corn oil was extracted    (21.09% by weight of feedstock). Solvent/feed ratio of about 12/1.-   Trail 8: 100 ml extraction of corn germ: 7000 psi and 80° C. 35.55 g    of corn germ feedstock was ground and sieved, and placed in a 100 ml    extraction vessel and extracted with pure carbon dioxide at a    pressure of 7000 psi and a temperature of 80° C. The flow rate was 4    liters/minute. A total of 7.40 g of yellow corn oil was extracted    (20.81% by weight of feedstock). Solvent/feed ratio of about 12/1.-   Trial 9: 100 ml extraction of corn germ: 6,000 psi and 85° C. 35.55    g of corn germ feedstock was ground and sieved, and placed in a 100    ml extraction vessel and extracted with pure carbon dioxide at a    pressure of 6000 psi and a temperature of 85° C. The flow rate was 4    liters/minute. A total of 7.52 g of yellow corn oil was extracted    (21.15% by weight of feedstock). Solvent/feed ratio of about 18/1.-   Trial 10: 100 ml extraction of corn germ 1600 psi and 20° C. 35.55 g    of corn germ feedstock was ground and sieved, and placed in a 100 ml    extraction vessel and extracted with pure carbon dioxide at a    pressure of 1600 psi and an ambient temperature of 20° C. The flow    rate was 4 liters/minute. A total of 4.22 g of yellow corn oil was    extracted (11.87% by weight of feedstock). Solvent/feed ratio is    >65/1.

The plots shown in the Figures are the result of these trials or trailssimilarly performed.

As can be easily understood from the foregoing, the basic concepts ofthe present invention may be embodied in a variety of ways whichincludes the best mode of the invention. The invention involves numerousand varied corn germ oil extraction devices and methods of extractingcorn oil from corn germ whether derived from conventional corn millingprocesses, from the kernel fractionation processes incorporated byreference, or otherwise. While certain examples are provided in thecontext of dry corn fractionation processes, it is not intended thatthese examples limit the use of the invention to corn germ derivedsolely from these inventive dry corn fractionation process (17), butrather are intended to be illustrative such that a person of ordinaryskill in the art can make and use the invention in the context of thenumerous and varied processes that produce an amount of corn germ fromwhich corn germ oil (23) can be extracted.

As such, the particular embodiments or elements of the inventiondisclosed by the description or shown in the figures or tablesaccompanying this application are not intended to be limiting, butrather exemplary of the numerous and varied embodiments genericallyencompassed by the invention or equivalents encompassed with respect toany particular element thereof. In addition, the specific description ofa single embodiment or element of the invention may not explicitlydescribe all embodiments or elements possible; many alternatives areimplicitly disclosed by the description and figures.

It should be understood that each element of an apparatus or each stepof a method may be described by an apparatus term or method term. Suchterms can be substituted where desired to make explicit the implicitlybroad coverage to which this invention is entitled. As but one example,it should be understood that all steps of a method may be disclosed asan action, a means for taking that action, or as an element which causesthat action. Similarly, each element of an apparatus may be disclosed asthe physical element or the action which that physical elementfacilitates. As but one example, the disclosure of an “extractor” shouldbe understood to encompass disclosure of the act of “extracting”—whetherexplicitly discussed or not—and, conversely, were there effectivelydisclosure of the act of “extracting”, such a disclosure should beunderstood to encompass disclosure of a “extractor” and even a “meansfor extracting.” Such alternative terms for each element or step are tobe understood to be explicitly included in the description.

In addition, as to each term used it should be understood that unlessits utilization in this application is inconsistent with suchinterpretation, common dictionary definitions should be understood toincluded in the description for each term as contained in the RandomHouse Webster's Unabridged Dictionary, second edition, each definitionhereby incorporated by reference.

Thus, the applicant(s) should be understood to claim at least: i) eachof the kernel fractionation devices or systems herein disclosed anddescribed, ii) the related methods disclosed and described, iii)similar, equivalent, and even implicit variations of each of thesedevices and methods, iv) those alternative embodiments which accomplisheach of the functions shown, disclosed, or described, v) thosealternative designs and methods which accomplish each of the functionsshown as are implicit to accomplish that which is disclosed anddescribed, vi) each feature, component, and step shown as separate andindependent inventions, vii) the applications enhanced by the varioussystems or components disclosed, viii) the resulting products producedby such systems or components, ix) methods and apparatuses substantiallyas described hereinbefore and with reference to any of the accompanyingexamples, x) the various combinations and permutations of each of theprevious elements disclosed.

The background section of this patent application provides a statementof the field of endeavor to which the invention pertains. This sectionmay also incorporate or contain paraphrasing of certain United Statespatents, patent applications, publications, or subject matter of theclaimed invention useful in relating information, problems, or concernsabout the state of technology to which the invention is drawn toward. Itis not intended that any United States patent, patent application,publication, statement or other information cited or incorporated hereinbe interpreted, construed or deemed to be admitted as prior art withrespect to the invention.

The claims set forth in this specification are hereby incorporated byreference as part of this description of the invention, and theapplicant expressly reserves the right to use all of or a portion ofsuch incorporated content of such claims as additional description tosupport any of or all of the claims or any element or component thereof,and the applicant further expressly reserves the right to move anyportion of or all of the incorporated content of such claims or anyelement or component thereof from the description into the claims orvice-versa as necessary to define the matter for which protection issought by this application or by any subsequent application orcontinuation, division, or continuation-in-part application thereof, orto obtain any benefit of, reduction in fees pursuant to, or to complywith the patent laws, rules, or regulations of any country or treaty,and such content incorporated by reference shall survive during theentire pendency of this application including any subsequentcontinuation, division, or continuation-in-part application thereof orany reissue or extension thereon.

The claims set forth below are intended to describe the metes and boundsof a limited number of the preferred embodiments of the invention andare not to be construed as the broadest embodiment of the invention or acomplete listing of embodiments of the invention that may be claimed.The applicant does not waive any right to develop further claims basedupon the description set forth above as a part of any continuation,division, or continuation-in-part, or similar application.

We claim:
 1. A corn oil extraction system, comprising: a) a at least oneextractor vessel; b) an amount of corn germ having a substantially fixedlocation inside said at least one extractor vessel; c) an amount ofsupercritical carbon dioxide fluidly engaged to said amount of corn germinside said at least one extractor vessel; d) a heat source whichmaintains said amount of supercritical carbon dioxide at a temperaturein a range of about 85° C. and about 120° C.; e) a pressure generatorwhich maintains said amount of supercritical carbon dioxide at apressure in a range of about 8500 psi and about 12,000 psi; f) aneffluent monitor which monitors an amount of corn oil solubilized insaid amount of supercritical carbon dioxide; g) a temperature adjustmentelement coupled to said heat source; and h) a pressure adjustmentelement coupled to said pressure generator, said temperature adjustmentelement and said pressure adjustment element responsive to said effluentmonitor, said temperature adjustment element and said pressureadjustment element adjusting said temperature and said pressure based onmonitoring said amount of corn oil solubilized in said amount ofsupercritical carbon dioxide to achieve a preselected corn germextraction efficiency profile.
 2. The corn oil extraction system ofclaim 1, wherein said temperature adjustment element and said pressureadjustment element continuously adjust said temperature of said amountof supercritical carbon dioxide between about 85° C. and about 120° C.and said pressure of said amount of carbon dioxide between 8,500 psi and12,000 psi to to extract said amount of corn germ with said amount ofsupercritical carbon dioxide at a ratio of between about 2:1 to about6:1 (wt/wt) to said amount of corn oil having a yield of greater than 18percent of the weight of said corn germ.
 3. The corn oil extractionsystem of claim 2 wherein said ratio comprises about 2:1 to about 5:1(wt/wt).
 4. The corn oil extraction system of claim 3 further comprisinga duration of time of between about 10 and about 30 minutes.
 5. The cornoil extraction system of claim 1, further comprising a comminutor whichreduces particle size of said amount of corn germ fluidically engaged tosaid amount of supercritical carbon dioxide in said corn germ extractionzone to less than about 30 mesh.
 6. The corn oil extraction system ofclaim 1, further comprising a water removal element coupled to saidamount of supercritical carbon dioxide which reduces an amount of waterin said amount of supercritical carbon dioxide which fluidically engagessaid amount of corn germ inside of said corn germ extraction zone tobetween about one percent by weight to about seven percent by weight. 7.The corn oil extraction system of claim 6, wherein said amount of corngerm located inside said corn germ extraction zone contains an amount ofwater in the range of about ten percent by weight to about fourteenpercent by weight prior to fluidic engagement with said amount ofsupercritical carbon dioxide inside said corn germ extraction zone. 8.The corn oil extraction system of claim 7, further comprising an amountof extracted corn germ generated by fluidic engagement with said amountof supercritical carbon dioxide inside said corn germ extraction zone,wherein said amount of extracted corn germ contains an amount of waterin the range of about one percent by weight to about seven percent byweight.
 9. The corn oil extraction system of claim 8, further comprisingan amount of distillation soluble having an amount of solids in therange of about 20 percent by weight to about 60 percent by weight mixedwith said amount of extracted corn germ containing an amount of water inthe range of about one percent by weight to about seven percent byweight sufficient to increase said amount of water contained by saidamount of extracted corn germ to between eight percent by weight toabout fourteen percent by weight.
 10. The corn oil extraction system ofclaim 9, further comprising an amount of distillation soluble having anamount of solids in the range of about 20 percent by weight to about 60percent by weight mixed with said amount of extracted corn germcontaining an amount of water in the range of about one percent byweight to about seven percent by weight sufficient to increase saidamount of water contained by said amount of extracted corn germ togreater than fourteen percent by weight, and further comprising a dryercapable of reducing the amount of water contained by said amount of corngerm mixed with said amount of distillation soluble having said amountof solids in the range of about 30 percent by weight to about 60 percentby weight to between about eight percent by weight to about fourteenpercent by weight.